On the ultrastructure of resting cambium of Fagus sylvatica L.

Cells of the resting cambium contain strands of smooth endoplasmic reticulum which is often arranged as a series of parallel membranes. Single membrane bound bodies of different types including lipid droplets, protein bodies, many different intermediate forms, and structures that are empty and vacuolelike are present. The possibility that vacuoles are formed by the progressive dissolution of stored lipids and protein, during the onset of cambial activity, is suggested.